Laboratory Tests

On this page

Basics

• Summary
• Start Here

Learn More

• Specifics

See, Play and Learn

• Videos and Tutorials

Research

• Journal Articles

Resources

• Reference Desk
• Find an Expert

For You

• Children

Summary

Laboratory tests check a sample of your blood, urine, or body tissues. A technician or your doctor analyzes the test samples to see if your results fall within the normal range. The tests use a range because what is normal differs from person to person. Many factors affect test results. These include:

• Your sex, age and race
• What you eat and drink
• Medicines you take
• How well you followed pre-test instructions

Your doctor may also compare your results to results from previous tests. Laboratory tests are often part of a routine checkup to look for changes in your health. They also help doctors diagnose medical conditions, plan or evaluate treatments, and monitor diseases.

Start Here

• How to Prepare for a Lab Test (National Library of Medicine) Also in Spanish
• How to Understand Your Lab Results (National Library of Medicine) Also in Spanish
• Lab Test Information (National Library of Medicine) Also in Spanish
• Tests Used In Clinical Care (Food and Drug Administration)
• Understanding Laboratory Tests (National Cancer Institute) Also in Spanish

Specifics

• At-Home Medical Tests (National Library of Medicine) Also in Spanish
• Differential Diagnosis (National Library of Medicine) Also in Spanish
• Fasting for a Blood Test (National Library of Medicine) Also in Spanish
• How to Cope with Medical Test Anxiety (National Library of Medicine) Also in Spanish
• How to Read Your Pathology Report (College of American Pathologists)
• How You Can Get the Best Results with Home Use Tests (Food and Drug Administration)
• Stool Tests (Nemours Foundation) Also in Spanish
• Venous Sampling (American College of Radiology; Radiological Society of North America) Also in Spanish
• What You Need to Know About Blood Testing (National Library of Medicine) Also in Spanish

Videos and Tutorials

• Getting a Urine Test (For Kids) (Nemours Foundation) Also in Spanish
• Reading Your Pathology Report (College of American Pathologists)

Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)

• Article: Outcomes of laboratory-confirmed SARS-CoV-2 infection in the Omicron-driven fourth wave compared...
• Article: Lessons from Theranos - Restructuring Biomedical Innovation.
• Article: Variation in Laboratory Reports: Causes other than Laboratory Error.
• Laboratory Tests -- see more articles

Reference Desk

• Glossary (Food and Drug Administration)

Find an Expert

• Accredited Laboratory and Biorepository Directory (College of American Pathologists)

Children

• Basic Blood Chemistry Tests (For Parents) (Nemours Foundation)
• Biobanks (For Parents) (Nemours Foundation)
• Blood Culture (For Parents) (Nemours Foundation)
• Getting a Blood Test (For Parents) (Nemours Foundation)
• How to Prepare Your Child for a Lab Test (National Library of Medicine) Also in Spanish
• Types of Blood Tests (For Parents) (Nemours Foundation)